added warning message for broken SWFs.

diff --git a/src/swfextract.c b/src/swfextract.c
index 81b7a48..a5f549a 100644 (file)
--- a/src/swfextract.c
+++ b/src/swfextract.c
@@ -285,7 +285,9 @@ void extractTag(SWF*swf, char*filename)
        changed = 0;
        for(t=0;t<65536;t++) {
           if(used[t] && !(used[t]&2)) {
-            if(tags[t]->id==ST_DEFINESPRITE) {
+            if(tags[t]==0) {
+                msg("<warning> ID %d is referenced, but never defined.", t);
+            } else if(tags[t]->id==ST_DEFINESPRITE) {
                 TAG*tag = tags[t];
                 while(tag->id != ST_END)
                 {